Karbid k\u0159em\u00edku, ozna\u010dovan\u00fd tak\u00e9 jako karborundum\/karbornm\/, je mimo\u0159\u00e1dn\u011b tvrd\u00e1 a odoln\u00e1 krystalick\u00e1 slou\u010denina k\u0159em\u00edku a uhl\u00edku, kter\u00e1 se ji\u017e od konce 19. stolet\u00ed pou\u017e\u00edv\u00e1 jako pr\u016fmyslov\u00fd materi\u00e1l.<\/p>\n
A\u010dkoli se moissanit v p\u0159\u00edrod\u011b vyskytuje v meteoritech a kimberlitech, v\u011bt\u0161ina SiC se nyn\u00ed vyr\u00e1b\u00ed synteticky bu\u010f rozpou\u0161t\u011bn\u00edm uhl\u00edku v roztaven\u00e9m k\u0159em\u00edku, nebo chemickou depozic\u00ed z par.<\/p>\n
Vynikaj\u00edc\u00ed tepeln\u00e1 vodivost karbidu k\u0159em\u00edku mu umo\u017e\u0148uje odol\u00e1vat vysok\u00fdm provozn\u00edm teplot\u00e1m. Tato vlastnost pom\u00e1h\u00e1 rychle a \u00fa\u010dinn\u011b odv\u00e1d\u011bt teplo a chr\u00e1n\u00ed jej p\u0159ed roztaven\u00edm nebo prasknut\u00edm v n\u00e1ro\u010dn\u00fdch podm\u00ednk\u00e1ch.<\/p>\n
Chr\u00e1n\u00ed za\u0159\u00edzen\u00ed p\u0159ed opot\u0159eben\u00edm a pom\u00e1h\u00e1 prodlou\u017eit jeho \u017eivotnost. D\u00edky n\u00edzk\u00e9mu koeficientu tepeln\u00e9 rozta\u017enosti a vynikaj\u00edc\u00ed tvrdosti je odoln\u00fd i v\u016f\u010di mechanick\u00e9mu nam\u00e1h\u00e1n\u00ed, jako je t\u0159en\u00ed a od\u011br.<\/p>\n
\u010cern\u00fd karbid k\u0159em\u00edku se vyzna\u010duje p\u0159\u00edsn\u011b kontrolovanou velikost\u00ed \u010d\u00e1stic, kter\u00e1 zaji\u0161\u0165uje v\u00fdjime\u010dnou \u0159eznou rychlost a povrchovou \u00fapravu, tak\u017ee je vhodn\u00fd pro \u0159adu aplikac\u00ed, jako jsou sklovit\u00e9 a prysky\u0159i\u010dn\u00e9 brusn\u00e9 kotou\u010de, tryskac\u00ed zrna\/prachov\u00e9 sm\u011bsi, sm\u011bsi, lapov\u00e1n\u00ed le\u0161t\u011bn\u00ed neklouzav\u00fdch a dr\u00e1tov\u00fdch pil k\u0159em\u00edku a k\u0159emene.<\/p>\n
Karborundov\u00e1 grafika, tradi\u010dn\u00ed technika kol\u00e1\u017ee, p\u0159i n\u00ed\u017e se na hlin\u00edkovou desku nan\u00e1\u0161\u00ed karborundov\u00e1 dr\u0165 a inkoust a pot\u00e9 se tiskne na v\u00e1lcov\u00e9m tiskov\u00e9m stroji, \u010d\u00edm\u017e vznikaj\u00ed tisky na pap\u00ed\u0159e s organickou strukturou, kter\u00e1 vynik\u00e1 jeho trvanlivost\u00ed.<\/p>\n
SiC je extr\u00e9mn\u011b tvrd\u00fd materi\u00e1l (9 stup\u0148\u016f Mohsovy stupnice). Nav\u00edc je d\u00edky sv\u00e9 odolnosti proti ot\u011bru vhodn\u00fd pro aplikace zahrnuj\u00edc\u00ed keramick\u00e9 brzdov\u00e9 kotou\u010de sportovn\u00edch automobil\u016f a nepr\u016fst\u0159eln\u00e9 vesty a tak\u00e9 pro t\u011bsn\u011bn\u00ed h\u0159\u00eddel\u00ed \u010derpadel. Krom\u011b toho tento materi\u00e1l odol\u00e1v\u00e1 extr\u00e9mn\u011b vysok\u00fdm teplot\u00e1m a z\u00e1rove\u0148 z\u016fst\u00e1v\u00e1 neporu\u0161en\u00fd p\u0159i kontaktu s jin\u00fdmi tvrd\u00fdmi materi\u00e1ly, jako je ocel.<\/p>\n
Vykazuje vynikaj\u00edc\u00ed odolnost proti oxidaci a\u017e do teploty p\u0159ibli\u017en\u011b 1400 \u00b0C a je nerozpustn\u00fd ve vod\u011b, alkoholu a kyselin\u00e1ch krom\u011b kyseliny fluorovod\u00edkov\u00e9.<\/p>\n
Zelen\u00fd SIC lze vyrobit z \u010dist\u00e9ho k\u0159emi\u010dit\u00e9ho p\u00edsku a ropn\u00e9ho koksu, zpracovat r\u016fzn\u00fdmi metodami tv\u00e1\u0159en\u00ed a slinovat p\u0159i vysok\u00fdch teplot\u00e1ch v elektrick\u00e9 peci s vnit\u0159n\u00edm odporem, \u010d\u00edm\u017e se z\u00edskaj\u00ed jak lepen\u00e9, tak reak\u010dn\u011b lepen\u00e9 v\u00fdrobky. Spole\u010dnost Saint-Gobain Performance Ceramics & Refractories pou\u017e\u00edv\u00e1 tento produkt p\u0159i v\u00fdrob\u011b brusiva, metalurgick\u00fdch a speci\u00e1ln\u00edch \u017e\u00e1ruvzdorn\u00fdch materi\u00e1l\u016f, jako\u017e i kompozit\u016f s kovovou matric\u00ed a n\u00e1bytku do pec\u00ed - nezapome\u0148te na v\u00fdrobu kompozitn\u00edch panc\u00e9\u0159ov\u00fdch syst\u00e9m\u016f!<\/p>\n
Karbid k\u0159em\u00edku prok\u00e1zal svou trvanlivost t\u00edm, \u017ee odol\u00e1v\u00e1 extr\u00e9mn\u00edm chemick\u00fdm podm\u00ednk\u00e1m a prost\u0159ed\u00ed, jako jsou brusn\u00e9 kotou\u010de v tov\u00e1rn\u00e1ch. Krom\u011b toho se pou\u017e\u00edv\u00e1 k brou\u0161en\u00ed a le\u0161t\u011bn\u00ed, jako\u017e i k pr\u016fmyslov\u00e9mu \u0159ez\u00e1n\u00ed a vrt\u00e1n\u00ed; nav\u00edc m\u00e1 vysokou odolnost proti opot\u0159eben\u00ed, tak\u017ee je vhodn\u00fd pro pou\u017eit\u00ed v metalurgii.<\/p>\n
Od konce 19. stolet\u00ed se silikonov\u00e1 pry\u017e pou\u017e\u00edv\u00e1 pro aplikace, jako jsou brusiva a brusn\u00e9 n\u00e1stroje, \u017e\u00e1ruvzdorn\u00e9 vyzd\u00edvky a v\u00e1lce pec\u00ed. D\u00edky sv\u00e9 v\u00fdjime\u010dn\u00e9 teplotn\u00ed odolnosti a odolnosti v\u016f\u010di tepeln\u00fdm \u0161ok\u016fm je silikonov\u00e1 pry\u017e vynikaj\u00edc\u00ed volbou materi\u00e1lu pro aplikace v letectv\u00ed a kosmonautice.<\/p>\n
Pr\u00e1\u0161ek karbidu k\u0159em\u00edku lze vyrobit taven\u00edm k\u0159emi\u010dit\u00e9ho p\u00edsku a koksu na b\u00e1zi uhl\u00ed v elektrick\u00e9 odporov\u00e9 peci p\u0159i teplot\u011b 2500 \u00b0C a n\u00e1sledn\u00fdm mlet\u00edm nebo tvarov\u00e1n\u00edm do pevn\u00fdch p\u0159edm\u011bt\u016f. V\u011bt\u0161\u00ed monokrystaly lze vyp\u011bstovat z \u010dist\u00e9ho k\u0159em\u00edku a uhl\u00edkov\u00fdch par v extr\u00e9mn\u00edm vakuu p\u0159i teplot\u011b 3500 stup\u0148\u016f C - podobn\u00fdmi postupy jako p\u0159i v\u00fdrob\u011b polovodi\u010dov\u00fdch desti\u010dek. Existuj\u00ed polymorfn\u00ed struktury, neboli struktury s r\u016fznou krystalovou strukturou, kter\u00e9 lze klasifikovat jako alfa nebo beta v z\u00e1vislosti na jejich atomov\u00e9 struktu\u0159e; alfa m\u00e1 obvykle hexagon\u00e1ln\u00ed (wurtzitovou) strukturu.<\/p>\n
Karbid k\u0159em\u00edku, neoxidov\u00fd keramick\u00fd materi\u00e1l, m\u00e1 schopnost odol\u00e1vat vysok\u00fdm teplot\u00e1m a ot\u011bru. Proto se ji\u017e dlouho pou\u017e\u00edv\u00e1 jako odoln\u00e1 sou\u010d\u00e1st p\u0159i brou\u0161en\u00ed, honov\u00e1n\u00ed a p\u00edskov\u00e1n\u00ed a \u010dasto se tak\u00e9 pou\u017e\u00edv\u00e1 v leteck\u00e9m a automobilov\u00e9m pr\u016fmyslu jako brusivo k le\u0161t\u011bn\u00ed r\u016fzn\u00fdch materi\u00e1l\u016f.<\/p>\n
Hlin\u00edk nereaguje s kyselinami a teplotami do 1600 stup\u0148\u016f Celsia. D\u00edky sv\u00e9 tetraedrick\u00e9 krystalov\u00e9 struktu\u0159e m\u016f\u017ee za ur\u010dit\u00fdch okolnost\u00ed odol\u00e1vat oxidaci - pokud je v\u0161ak del\u0161\u00ed dobu vystaven vysok\u00fdm koncentrac\u00edm kysl\u00edku, m\u016f\u017ee rychle oxidovat.<\/p>\n
K r\u016fzn\u00fdm metod\u00e1m vytv\u00e1\u0159en\u00ed keramiky r\u016fzn\u00fdch tvar\u016f a velikost\u00ed pat\u0159\u00ed rekrystalizace, lisov\u00e1n\u00ed za tepla, mikrovlnn\u00e9 sp\u00e9k\u00e1n\u00ed, beztlakov\u00e9 sp\u00e9k\u00e1n\u00ed a reak\u010dn\u00ed sp\u00e9k\u00e1n\u00ed. Keramika se hojn\u011b pou\u017e\u00edv\u00e1 jako sou\u010d\u00e1st tepeln\u011b n\u00e1ro\u010dn\u00fdch \u017e\u00e1ruvzdorn\u00fdch materi\u00e1l\u016f a keramiky pou\u017e\u00edvan\u00e9 jako sou\u010d\u00e1sti nepr\u016fst\u0159eln\u00fdch panc\u00ed\u0159\u016f; d\u00edky sv\u00e9 tuhosti a pevnosti je nav\u00edc vhodn\u00e1 i pro zrcadla astronomick\u00fdch teleskop\u016f.<\/p>","protected":false},"excerpt":{"rendered":"
Silicon carbide, also referred to as carborundum\/karbornm\/ is an exceptionally hard and durable crystalline compound of silicon and carbon that […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"footnotes":""},"categories":[5],"tags":[],"class_list":["post-40","post","type-post","status-publish","format-standard","hentry","category-product-related"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/posts\/40","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/comments?post=40"}],"version-history":[{"count":1,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/posts\/40\/revisions"}],"predecessor-version":[{"id":41,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/posts\/40\/revisions\/41"}],"wp:attachment":[{"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/media?parent=40"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/categories?post=40"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/siliconcarbideceramic.net\/cs\/wp-json\/wp\/v2\/tags?post=40"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}